LA-5

Question 1

chemical bonds

Answer 1

electrostatic forces holding groups of atoms or ions together

Question 2

octet

Answer 2

set of 8 electrons in valence shell

Question 3

unpaired dots

Answer 3

bonding capactiy

Question 4

cation

Answer 4

positively charged particle–> loss of electrons by an atom with LOW ionization energy (metals)

Question 5

anion

Answer 5

negatively charges particle–> gain of electrons by an atom with HIGH electron affinity (nonmetals)

Question 6

ionic bonds

Answer 6

transfer of valence electrons from one atom to another; resulting ions are electrostatically attracted to one another; the attraction of these oppositely charged ions is the ionic bond

Question 7

ionization energy

Answer 7

energy to remove and electron

Question 8

electron affinity

Answer 8

the energy to add an electron

Question 9

what happens when two ions bond

Answer 9

more energy is released, making the process exothermic

Question 10

lattice energy

Answer 10

the energy required to completely separate one mole of a solid ionic compound into gaseous ions
lattice energy increases as Q increases and/or r decreases

Question 11

Trends in Lattice Energy: Ion Size

Answer 11

larger ion = weaker attraction = smaller lattice energy

Question 12

Trends in Lattice Energy: Ion Charge

Answer 12

larger charge = stronger attraction = larger lattice energy

Question 13

Characteristics of Ionic bonds

Answer 13

1) high melting and boiling points, 2) ionic solids are hard compared to most molecular solids, 3) ionic solids do not conduct electricity, 4) ionic compounds conduct electricity in liquid or when dissolved in water, 5) ionic solids are brittle, when struck they shatter

Question 14

covalent bond

Answer 14

two nonmetals bond, share electrons-> covalent bond

Question 15

bond length

Answer 15

distance between the atoms when energy is at a minimum

Question 16

coordinate covalent bond

Answer 16

both electrons are donated by one of the atoms

Question 17

polar covalent bond

Answer 17

the bonding electrons spend more time near one of the two atoms involved

Question 18

nonpolar bond

Answer 18

the bonding electrons are shared equally

Question 19

electronegativity

Answer 19

a measure of the ability of an atom in a molecule to draw bonding electrons to itself

Question 20

diff in electronegativity 0.1-0.4

Answer 20

nonpolar covalent

Question 21

diff in electronegativity 0

Answer 21

pure covalent

Question 22

diff in electronegativity 0.5-1.9

Answer 22

polar covalent

Question 23

diff in electronegativity larger than or equal to 2.0

Answer 23

ionic

Question 24

delocalized bonding

Answer 24

one pair of bonding electrons is spread over a number of atoms

Question 25

electron deficient

Answer 25

molecules with atoms having fewer than eight electrons

Question 26

free radicals

Answer 26

molecules having odd number of electrons

Question 27

expanded valence shell

Answer 27

molecules with atoms having more than an octet

Question 28

bond length/distance

Answer 28

the distance between nuclei in a bond

Question 29

bond order

Answer 29

determined by the Lewis structure, is the number of pairs of electrons in a bond
- as bond order increases, the bond gets shorter and stronger

Question 30

bond energy

Answer 30

energy needed to break 1 mole of covalent bonds in the gas phase

Question 31

breaking bonds _______ energy; forming bonds ______ energy

Answer 31

consumes, releases

Question 32

Lewis structure

Answer 32

shows atoms and bonds, but not spatial orientations

Question 33

molecular models

Answer 33

show orientations and bond angles; help us understand physio-chemical properties

Question 34

VSEPR Theory

Answer 34

geometric arrangement of electron pairs around atoms based on minimizing repulsion energy

Question 35

electron pair geometry

Answer 35

spatial arrangement of bonding electron pairs and lone pairs (non-bonding) of valence electrons

Question 36

molecular geometry

Answer 36

relative arrangement of atoms in molecule

Question 37

dipole moment

Answer 37

a measure of the degree of charge separation in a molecule

Question 38

hybridization

Answer 38

mixing of atomic orbitals to generate new sets of orbitals that form covalent bonds with other atoms

Question 39

hybrid atomic orbital

Answer 39

one of a set of equivalent orbitals created when specific atomic orbitals are mixed

Question 40

sigma bond

Answer 40

covalent bond having highest electron density between the two atoms along the bond axis; “Head-to-head” overlap of orbitals

Question 41

pi bond

Answer 41

electron density is concentrated above/below the bonding axis

Question 42

bond angle

Answer 42

angle defined by covalent bonds between 3 adjacent atoms

Question 43

polar molecule

Answer 43

• have nonzero dipole moments
• vectors of bond dipoles sum > zero